You could turn you final edit into a compound clip. Then create a new project at 1920x1080 and drop the compound clip in. That way you wouldn't have to render out a 4K file.

Another option, of course would be to start your timeline as 1920x1080. I haven't played around with 4K, so I don't know if working with 4K footage in an HD timeline is slower than working in 4K directly.

Great idea! Create compound clip and then drop it into an HD project ... I hadn't thought of that. So I don't have to export the edited clip it at all.

Note that I can't import initially into an HD project because I need to create a zoomed-in 16:9 crop (up to a 50% crop). I presume this needs to be done while editing a full-res clip 'cause otherwise I'd lose considerable detail.

BTW, the GH4 4K at 100mbps imports and plays just fine on my new (and somewhat souped-up) iMac. Rendering certainly takes awhile, but otherwise it's smooth as silk. I've read that this is not the case for 4K from a lot of other cameras. Another great thing is that I can record the 100mbps 4K in-camera to a fairly inexpensive Transcend 64GB UHS-1 SDXC card ($99). That's my kind of 4K ... very user-friendly!

[Lang Elliott]"BTW, the GH4 4K at 100mbps imports and plays just fine on my new (and somewhat souped-up) iMac. Rendering certainly takes awhile, but otherwise it's smooth as silk. I've read that this is not the case for 4K from a lot of other cameras."

Lang: Thanks for sharing your experience. I just did my first 4k shoot with the GH4 and I'm learning that my 2011 Macbook Pro does not handle the 4k MOV's from the camera well at all. They won't play back without major stuttering/frame-dropping. I can create proxy files which solves the problem, but it would be nicer to be able to cut the native files smoothly.

[Lang Elliott]"Another great thing is that I can record the 100mbps 4K in-camera to a fairly inexpensive Transcend 64GB UHS-1 SDXC card ($99). That's my kind of 4K ... very user-friendly!"

That is nice to know. I only bought one of new Sandisk U-3 64GB cards (for something like $250). I'm hopeful that Panasonic will get theirs out the door soon, since they are half the price.

When I import the 4K clip, I choose not to make optimized media. I then import the clip and set spatial conform to "none" in the inspector, which displays the 4K at full resolution, extended way out from the 16:9 frame margins. If I then view the clip at a low screen viewing percentage, I am able to see the transform handles and pull them in to my liking, as well as adjust the cropping by moving the transform window around.

I do bird videos and this workflow will be terrific for HD projects. Shooting in 4K is equivalent to using a zoom lens and will allow me to shoot without worrying so much about exact framing, which is a total pain in the arse to adjust when shooting at focal lengths approaching 3000mm. I will be able to focus and frame quickly, and then crop to my liking in post without losing any resolution (for HD). Wow!

If you recorded some videos by Panasonic GH4, you may like editing the 4K videos. Of course, Final Cut Pro, Avid Media Composer, iMovie, Adobe Premiere Pro are all your choices. But, we can’t import Panasonic GH4 4K to FCP/iMovie/Avid/Premiere Pro directly due to the codec incompatibility. Something else, there's actually no way to edit a 4K project in FCP 7/iMovie/Avid natively. In this case, downscale 4K to 1080P is really necessary since 1080p would be the best settings. It will save you both time and trouble, and all you need is to drag the result videos for prompt editing. And it also brings easier 4K playback if you want to view the 4K videos on your TV or other media devices. You can google a professional 4K to 1080p converter to get the work done.